Josh: Deep technical PS/ValuePoint pages with verified sources (IBM HMM S61G-1423, kev009 mirror)

2026-05-23T14:33:46Z

Deep technical PS/ValuePoint pages with verified sources (IBM HMM S61G-1423, kev009 mirror)

New page

This guide documents capacitor diagnosis and replacement for the '''[[IBM PS/ValuePoint]]''' family — machine types '''6381 / 6382 / 6384 / 6387'''. PS/ValuePoint planars predate the early-2000s '''capacitor plague''' that affects the [[IBM IntelliStation]] line, and they '''do not''' use the soldered barrel NiCd cells that destroy certain PS/2 model 30 / 56 / 57 / 76 / 77 boards. The PS/ValuePoint's main capacitor concern is the '''floppy drive logic board''' SMD electrolytic, with secondary concerns being aged 100 / 145 / 200 W PSU electrolytics.

== Safety Warning ==

All PS/ValuePoint PSUs contain mains-rectified bulk capacitors that hold a lethal charge after power-off. Before any PSU work:

# Power off and unplug the mains lead.
# Wait at least 30 seconds.
# Discharge the bulk capacitor through a 1 kΩ / 5 W resistor.
# Verify with a multimeter.

== Battery — IMPORTANT CLARIFICATION ==

'''The PS/ValuePoint planar battery is a standard CR2032 lithium coin cell.''' It is '''NOT''' a barrel NiCd, '''NOT''' a Dallas DS1287 / DS1287A integrated RTC module, and '''NOT''' a Varta-style rechargeable nickel cell. This means:

* PS/ValuePoint planars are '''not''' affected by the famous Varta / NiCd leakage that destroys certain PS/2 Model 30 / 56 / 57 / 76 / 77, IBM ThinkPad, and Compaq motherboards.
* Replacement is a tool-free swap from a snap clip at position B1 / BT1.
* No desoldering is required.

The IBM Product Description repeats "Lithium battery" for every PS/ValuePoint variant including 6381 SX, 6381 DX/DX2, 6382/S, 6384/D, 6384 P60/D, and 6387/T.<ref>http://ps-2.kev009.com/pcpartnerinfo/ctstips/27ae.htm</ref><ref>http://ps-2.kev009.com/pcpartnerinfo/ctstips/e1f6.htm</ref>

Although CR2032 cells very rarely leak, they '''can''' do so under unusual conditions; restorer field reports document a leaked CR2032 specimen pulled from a 6381-Fxx, with minimal damage to the planar.<ref>https://www.zx.net.nz/computers/ibm/psvaluepoint_425sxsi/</ref>

If you find a leaked CR2032:

# Remove the cell with plastic tweezers (do not short the contacts).
# Neutralise the alkaline residue (typical CR2032 leak chemistry is KOH-style) with a small amount of isopropanol followed by a small amount of dilute white vinegar, then a thorough rinse with deionised water on a foam swab.
# Dry the area completely with compressed air before refitting a fresh cell.
# Check the planar power-supply circuitry around B1 / BT1 for any visible trace damage; repair with 30 AWG enamelled wire if necessary.

== Floppy Drive Logic Board — Primary Cap Replacement Target ==

The most-likely-to-fail capacitor on a PS/ValuePoint system is the '''Alps floppy drive logic board SMD aluminium electrolytic''' next to the power connector. Hands-on documentation of a 6381-Fxx specimen reports "The Alps floppy drive has a surface-mount aluminium electrolytic capacitor next to the power connector which may be leaking and in need of replacement."<ref>https://www.zx.net.nz/computers/ibm/psvaluepoint_425sxsi/</ref>

Symptoms of a failed floppy drive electrolytic:

* Floppy reads OK but writes are corrupt.
* Drive intermittent — works cold, fails warm.
* Brown residue around cap base on the drive logic board.
* Drive activity LED dim or flickering.

Replacement procedure:

# Power off, unplug, discharge.
# Remove the floppy drive from the chassis.
# Identify the SMD electrolytic next to the drive power connector (usually 47 µF / 16 V or 22 µF / 16 V).
# With a hot-air rework station or fine-tipped soldering iron, remove the cap. Lift straight up; do not pry sideways or you may lift the pad.
# Clean the pad with solder wick.
# Wash the area with isopropyl alcohol.
# Fit a replacement '''47 µF / 16 V''' (or 22 µF / 16 V to match the original — read the cap top) SMD low-ESR aluminium electrolytic or '''through-hole tantalum''' of equal value.
# Verify polarity matches the silkscreen.

Typical Alps floppy logic board cap list:

{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''Alps PS/ValuePoint floppy drive cap replacement summary'''
! Value !! Voltage !! Type !! Position
|-
| 47 µF || 16 V || SMD aluminium → tantalum or SMD low-ESR || Spindle motor driver / power connector vicinity
|-
| 22 µF || 16 V || SMD aluminium → tantalum or SMD low-ESR || Power filter (some submodels)
|-
| 10 µF || 16 V || SMD aluminium → tantalum or SMD low-ESR || Head amp / IC bypass
|}

== Planar Capacitor Inspection ==

PS/ValuePoint planars (1992–1995) are old enough to warrant capacitor inspection but '''predate the famous early-2000s capacitor plague''' that takes down [[IBM IntelliStation]] M Pro / Z Pro Pentium 4 boards. The PS/ValuePoint planar carries:

* '''Through-hole aluminium electrolytic''' caps in the +5 V and +12 V power input area (typical values 100–470 µF / 16–25 V).
* '''Tantalum''' decoupling caps around the CPU socket, video chip, and chipset (10 µF / 16 V typical).
* '''Surface-mount aluminium electrolytic''' caps on some submodels (6384 /D and 6387 /T are most common).

Failure modes:

* Tantalum '''short circuit''' — pulls down +5 V; system will not POST.
* Aluminium electrolytic '''leakage''' — corrodes traces; intermittent fault.
* Both are uncommon on this generation but should be inspected.

Diagnostic procedure (tantalum short):

# Set multimeter to diode test.
# Probe each tantalum in-circuit: black probe to ground, red probe to rail side. Good cap reads as open / high resistance; failed (shorted) cap reads close to 0 Ω.
# Remove the cap to confirm out-of-circuit.
# Replace with a fresh tantalum or low-ESR ceramic of equal value, equal or higher voltage rating.

Representative planar cap list (varies by submodel):

{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''PS/ValuePoint planar capacitor replacement summary (representative)'''
! Value !! Voltage !! Type !! Quantity (approx) !! Notes
|-
| 10 µF || 16 V || Tantalum || ~10–20 || IC bypass around CPU, video, chipset
|-
| 22 µF || 16 V || Tantalum || ~4–6 || Memory bank decoupling
|-
| 100 µF || 16 V || Aluminium electrolytic, 105 °C low-ESR || 2–3 || Power input filtering
|-
| 220 µF || 16 V || Aluminium electrolytic, 105 °C low-ESR || 1–2 || Power input filtering
|-
| 470 µF || 16 V || Aluminium electrolytic, 105 °C low-ESR || 1–2 || Bulk filter near power connector
|}

== PSU Recap ==

PS/ValuePoint PSUs are '''AT-style''' (5-pin + 6-pin power connector, not ATX). Three power levels:

* '''100 W''' — 6381-Si entry boards.
* '''145 W''' — 325T and original 1992 6384.
* '''200 W''' — 6382 /S, 6384 /D, 6384 P60/D, 6387 /T.

Common topology: single-board switching supply with primary / secondary stages.

* '''Primary side''' — bridge rectifier, X2 mains suppression cap, '''220 µF / 200 V''' (100 W / 145 W) or '''470 µF / 200 V''' (200 W) primary bulk, switching transistor, switching transformer.
* '''Secondary side''' — rectifier diodes, smoothing electrolytics, output chokes, optocoupler feedback.

=== 100 W / 145 W PSU Cap Values (Typical) ===

{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''PS/ValuePoint 100 W / 145 W PSU capacitor replacement summary (typical)'''
! Value !! Voltage !! Type !! Typical position
|-
| 2200 µF || 16 V || Low-ESR aluminium, 105 °C || +5 V smoothing × 1
|-
| 1000 µF || 16 V || Low-ESR aluminium, 105 °C || +5 V auxiliary
|-
| 470 µF || 35 V || Aluminium electrolytic, 105 °C || +12 V smoothing
|-
| 220 µF || 35 V || Aluminium electrolytic, 105 °C || −12 V smoothing
|-
| 100 µF || 16 V || Aluminium electrolytic, 105 °C || Bypass / feedback × 2
|-
| 100 µF || 50 V || Aluminium electrolytic, 105 °C || Primary auxiliary
|-
| 47 µF || 50 V || Aluminium electrolytic, 105 °C || Primary startup
|-
| 220 µF || 200 V || Aluminium electrolytic, 105 °C || Primary bulk (lethal-charge component)
|-
| 0.1 µF || 275 VAC || X2 class || Mains suppression — replace if RIFA-branded
|}

=== 200 W PSU Cap Values (Typical) ===

{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''PS/ValuePoint 200 W PSU capacitor replacement summary (typical)'''
! Value !! Voltage !! Type !! Typical position
|-
| 2200 µF || 16 V || Low-ESR aluminium, 105 °C || +5 V smoothing × 2
|-
| 1000 µF || 25 V || Low-ESR aluminium, 105 °C || +12 V smoothing
|-
| 470 µF || 35 V || Aluminium electrolytic, 105 °C || +12 V auxiliary
|-
| 220 µF || 35 V || Aluminium electrolytic, 105 °C || −12 V smoothing
|-
| 100 µF || 50 V || Aluminium electrolytic, 105 °C || Primary auxiliary × 2
|-
| 100 µF || 16 V || Aluminium electrolytic, 105 °C || Bypass / feedback × 2–3
|-
| 47 µF || 50 V || Aluminium electrolytic, 105 °C || Primary startup
|-
| 470 µF || 200 V || Aluminium electrolytic, 105 °C || Primary bulk (lethal-charge component)
|-
| 0.1 µF || 275 VAC || X2 class || Mains suppression — replace if RIFA-branded
|}

=== Recap Procedure ===

# Discharge the bulk capacitor; verify with a multimeter.
# Remove the PSU from the chassis (4 screws typically).
# Open the PSU housing.
# Photograph the board. Mark each electrolytic's polarity.
# Desolder each electrolytic with solder wick.
# Fit '''low-ESR''', '''105 °C''' replacements, equal capacitance, equal or higher voltage rating.
# Inspect the X2 mains suppression cap. If RIFA-branded or cracked / bulging, replace.
# Reassemble. Verify rails on the bench with a multimeter under a 1 A resistive load before refitting to the chassis.

== Video Card / Riser Capacitors ==

The PS/ValuePoint video is on-planar (Cirrus / Tseng / S3 / ATI Mach32); there is no removable video card on most submodels. The video subsystem decoupling caps are inspected as part of the planar inspection (above).

The '''ISA / VLB / PCI riser card''' carries no electrolytic capacitors (passive interconnect only) and does not require recap.

== L2 Cache Module Capacitors ==

The optional 128 KB or 256 KB L2 cache module that fits the 486 boards carries SMD ceramic decoupling caps only — no electrolytic caps. No recap is required.

== Hard Drive Logic Board Capacitors ==

PS/ValuePoint era IDE drives (Conner CFA-170A, IBM WD-style, Quantum ProDrive, Maxtor 7245, etc.) carry SMD electrolytics that age. Typical values on the drive logic board:

* '''47 µF / 16 V''' — spindle motor driver.
* '''10 µF / 25 V''' — head amp.
* '''22 µF / 16 V''' — sector buffer.

Modern alternative: replace the original IDE drive with a CompactFlash-to-IDE or XT-IDE / IDE2SD adapter — no recap needed, fast, reliable.

== Replacement Parts Summary ==

{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''PS/ValuePoint system-wide cap replacement summary'''
! Value !! Voltage !! Type !! Where
|-
| 10 µF || 16 V || Tantalum or SMD low-ESR || Planar IC bypass
|-
| 22 µF || 16 V || Tantalum or SMD low-ESR || Planar memory bank, drive sector buffer
|-
| 47 µF || 16 V || Tantalum or SMD low-ESR aluminium || '''Alps floppy drive logic board — primary failure position'''
|-
| 100 µF || 16 V || Aluminium electrolytic, 105 °C || Planar power input
|-
| 100 µF || 50 V || Aluminium electrolytic, 105 °C || PSU primary auxiliary
|-
| 220 µF || 16 V || Aluminium electrolytic, 105 °C || Planar power input
|-
| 220 µF || 35 V || Aluminium electrolytic, 105 °C || PSU −12 V smoothing
|-
| 220 µF || 200 V || Aluminium electrolytic, 105 °C || 100 W / 145 W PSU primary bulk
|-
| 470 µF || 16 V || Aluminium electrolytic, 105 °C || Planar bulk filter near power connector
|-
| 470 µF || 35 V || Aluminium electrolytic, 105 °C || PSU +12 V smoothing
|-
| 470 µF || 200 V || Aluminium electrolytic, 105 °C || 200 W PSU primary bulk
|-
| 1000 µF || 16 V / 25 V || Low-ESR aluminium, 105 °C || PSU +5 V / +12 V smoothing
|-
| 2200 µF || 16 V || Low-ESR aluminium, 105 °C || PSU +5 V smoothing × 1–2
|-
| 47 µF || 50 V || Aluminium electrolytic, 105 °C || PSU primary startup
|-
| 0.1 µF || 275 VAC || X2 class || PSU mains suppression
|}

== Polarity Reference ==

The PS/ValuePoint planar silkscreen marks the '''+''' (positive, rail) side of each tantalum with a small "+". Aluminium electrolytic caps show the negative side with a stripe and "−" on the can. Match these conventions.

[[File:IBM 5150 tantalum polarity reference.jpg|center|thumb|640px|Polarity reference for IBM motherboard tantalum capacitors. The convention applies to the PS/ValuePoint planar. (Image: minuszerodegrees.net)]]

A failed tantalum often shows '''no visible damage'''.

[[File:IBM 5150 failed tantalum visual example.jpg|right|thumb|300px|Failed tantalum on an IBM motherboard. (Image: minuszerodegrees.net)]]

== Post-Recap Verification ==

# Bench-test the planar with a known-good PSU and no peripherals.
# Verify rails at the planar power connector.
# Refit; power on; observe POST beep and memory count.
# Press F1 during memory count to enter Setup; verify all expected hardware (memory size, drive types) is detected.
# Run the Advanced Diagnostics Diskette for full system self-test.
# Run a sustained DOS or Windows session under load for several hours to confirm stability.

If any test fails after a recap, re-inspect the polarity of every replaced cap before suspecting another fault — reversed polarity is the most common error.

== When Not to Recap ==

If the PS/ValuePoint boots, POSTs cleanly, runs reliably with no errors and visual inspection shows no cap failure, the caps are within tolerance. PS/ValuePoint planars typically '''do not''' require recap unless:

* Floppy drive symptoms point to the Alps SMD electrolytic.
* PSU symptoms (random reboots under disk load, audible whine, smell of fish from venting RIFA X2) indicate aged secondaries.
* Visible electrolyte leakage on the planar.
* Bulged or leaking electrolytic anywhere visible.

== Related Pages ==

* [[IBM PS/ValuePoint]]
* [[IBM PS/ValuePoint Maintenance Guide]]
* [[IBM PS/ValuePoint Troubleshooting Guide]]
* [[Capacitor Failure Symptoms]]

== References ==

* [http://ps-2.kev009.com/pcpartnerinfo/ctstips/e1f6.htm IBM PS/ValuePoint Tips & Tricks, kev009 mirror]. '''Lithium battery''' confirmation (point 13).
* [http://ps-2.kev009.com/pcpartnerinfo/ctstips/27ae.htm IBM PS/ValuePoint Product Description]. Lithium battery for every variant.
* [http://ps-2.kev009.com/pcpartnerinfo/ctstips/a26e.htm IBM PS/ValuePoint System Board layouts]. B1/BT1 battery position.
* [http://ps-2.kev009.com/pcpartnerinfo/ctstips/ebaa.htm IBM PS/ValuePoint 6381-Fxx product description]. CR2032 battery, 100 W PSU.
* [https://www.zx.net.nz/computers/ibm/psvaluepoint_425sxsi/ zx.net.nz — IBM PS/ValuePoint 425SX/Si hands-on documentation]. CR2032 leakage report; Alps floppy SMD cap note (primary cap failure).
* [http://ps-2.kev009.com/pccbbs/valuepnt/s61g1423.pdf IBM Hardware Maintenance Manual S61G-1423-01 (Sep 1993)]. Authoritative HMM, FRU lists.
* [http://ps-2.kev009.com/basil.holloway/boo-to-pdf/S61G_1423_02.pdf IBM HMM S61G-1423-02 (Aug 1996)]. Updated HMM covering 638x and later 64xx machine types.
* [https://www.minuszerodegrees.net/failure/failure.htm Commonly Failing Electronic Components, minuszerodegrees.net].

{{Navbox-IBMComputers|state=collapsed}}

[[Category:IBM]]
[[Category:Capacitor Replacement Guides]]

IBM PS/ValuePoint Capacitor Replacement Guide - Revision history

Josh: Deep technical PS/ValuePoint pages with verified sources (IBM HMM S61G-1423, kev009 mirror)