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History of IBM 5150/5155/5160/5170 Motherboard Failure
at the Vintage Computer Forums


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Date Thread#Post Member Motherboard Cause   Comment
OCT06 4573 the xt guy 5150 RAM  
NOV06 5323 mR_Slug 5160 Tantalum cap  C56 (sits on +12V line)
JAN08 9601 dkedrowitsch 5170 BIOS ROM  Offline, determined that his 61X9265 EPROM had corrupted contents
MAR08 10510 crazypigeon 5150 Tantalum cap  One of six C6 on 16KB-64KB board. (+/- 12V lines)
  10510#11 flavio75 5160 Tantalum cap  
MAY08 10510#30 vwestlife 5150 Tantalum cap  64KB-256KB board. C7 nearest U5 (sits on -12V line).
MAY08 10961 dongfeng 5150 RAM  
JAN09 12538 Luke 5160 Tantalum cap  C58 (sits on -12V line)
MAR09 10961#12 tezza 5150 RAM  Last worked okay a few months previously.
MAR10 19696 rtwo 5155 BIOS ROM  U19
NOV10 22209#38 nestor 5150 RAM  64KB-256KB board. One faulty 4164 RAM chip in bank 0
JAN11 25230 Denniske1976 5160 Tantalum cap  C56 (sits on +12V line)
FEB11 24042#1 mikey99 5150 RAM  16KB-64KB board. One faulty 4116 RAM chip in bank 3.
MAR11 24223 framer 5150 BIOS ROM  U33
MAR11 23864#17 zoomgofstr 5155 RAM  
MAY11 25196 redhawk579 5160 Tantalum cap  C56 (sits on +12V line)
AUG11 26693#8 bettablue 5150 Tantalum cap  Multiple
DEC11 24042#8 mikey99 5150 RAM  One 4116 RAM chip. Same motherboard that failed in February.
MAY12 30371 DOS lives on 5170 RAM  Type 1 motherboard. One chip in bank 0.
MAY12 30521 CannedBread 5155 Tantalum cap  C58 (sits on -12V line)         (plus tantalum cap C8 on IBM CGA card)
JUN12 31172 latvija13 5155 2 x tantalum caps  C56 (sits on +12V line) or C58 (sits on -12V line)  -  both removed
SEP12 32659 marcoguy 5160 RAM  No longer seeing RAM above 128 KB.  Fix: Reseated RAM chips
OCT12 34083 madmaxamdam 5160 2 x tantalum caps  C56 (sits on +12V line) or C58 (sits on -12V line)  -  both removed
APR13 36547#54 PCFreek 5150 RAM  64KB-256KB board. One faulty 4164 RAM chip in bank 0
APR13 36547 PCFreek 5150 Multiple faults  16KB-64KB board #1. 74LS175 chip (U26) + faulty 4116 RAM chips.
APR13 36547 PCFreek 5150 RAM  16KB-64KB board #2. One 4116 RAM chip.
JUL13 38036 gkavner 5150 2 x tantalum caps  64KB-256KB board. Caps on +12V and -12V lines.
JUL13 38159 PCFreek 5150 Tantalum cap  16KB-64KB board. One of many caps on +12V line.
AUG13 38717#1 eXTended8088 5160 RAM  Faulty RAM in bank 0
AUG13 38814#12 framer 5160 Tantalum cap  C56 (sits on +12V line) or C58 (sits on -12V line)  -  both removed
AUG13 38893 camerongray 5160 Tantalum cap  C56 (sits on +12V line)
SEP13 39264 gkavner 5150 Tantalum cap  
NOV13 40187#22 giobbi 5160 Tantalum cap  C56 (sits on +12V line)
DEC13 40546#9 tezza 5160 Tantalum caps + RAM  C56 (sits on +12V line) and C58 (sits on -12V line) and faulty RAM in bank 0
JAN14 40780 Denniske1976 5160 2 x tantalum caps  C56 (sits on +12V line) and C58 (sits on -12V line)
JAN14 40814 VintageC 5155 Tantalum cap  C56 (sits on +12V line) or C58 (sits on -12V line)  -  both removed
JAN14 [email] Denniske1976 5160 Tantalum cap  C56 (sits on +12V line)
FEB14 41258 commodorejohn 5150 Tantalum caps  Caps on the +12V line and -12V lines
MAR14 41911 xave 5160 RAM  No longer seeing RAM above 64 KB.  Cause: Bad RAM chip in 64-128KB bank
MAR14 41950#8 awergh 5160 Tantalum caps  Caps on the +12V line and -12V lines
MAR14 42020#4 bjorn_and 5150 Tantalum cap  Cap on the -12V line
JUN14 43069 3pcedev 5160 RAM  
JUL14 43314 bobba84 5160 RAM  Via PM: "10 bad RAM chips".  5160 had been in a shed for 7 years.
AUG14 43857 PCFreek 5150 Tantalum cap  16KB-64KB board. One cap on the +12V line.
SEP14 44380#1 PCFreek 5150 Tantalum cap  16KB-64KB board #1.  One C6 (there are many C6's - used on both the -12V and +12V lines).
SEP14 44380#1 PCFreek 5150 Tantalum cap  16KB-64KB board #2.  Multiple C6 (there are many C6's - used on both the -12V and +12V lines).
SEP14 44504 codeman 5150 Tantalum cap  16KB-64KB board.
JAN15 46130 MauriceH 5160 RAM  No longer seeing RAM above 128 KB.  Cause: Bad RAM chip in 128-192KB bank
APR15 47099 Stone 5150 Tantalum cap  64KB-256KB board. The cap on the -12V line.
APR15 47254 romanon 5150 RAM  Faulty RAM in bank 0
APR15 46489 romanon 5170 keyboard controller  Faulty keyboard controller chip (U126)
MAY15 47399 gobabushka 5155 Tantalum caps  C56 (sits on +12V line) and C68 (sits on -5V line)
MAY15 47460 framer 5160 Tantalum cap + RAM  C56 (sits on +12V line) or C58 (sits on -12V line) - both removed.  Plus faulty RAM
MAY15 47524 Divad 5150 BIOS ROM + RAM  16KB-64KB board.  Faulty U33, plus faulty RAM in bank 0
AUG15 48622#6 max5160 5160 BIOS ROM  Faulty U18
AUG15 48683 vossi 5160 Tantalum cap  C56 (sits on +12V line)
AUG15 48788 Chromedome45 5150 RAM  Faulty RAM in bank 0
SEP15   elwro07 5155 Tantalum caps  C56 (sits on +12V line) and C58 (sits on -12V line)
NOV15 49825 Gerardcjat 5155 Tantalum caps  C56 (sits on +12V line) and C58 (sits on -12V line)         (plus tantalum cap C8 on IBM CGA card)
NOV15 49771#37 A Fox 5160 IC  Faulty U27
NOV15 49771#38 A Fox 5160 IC + RAM  Faulty U11 and U20, plus six faulty 4164
DEC15 49160 fafonso 5150 RAM  Faulty RAM in bank 0
DEC15 50396 Ozzuneoj 5150 RAM  Faulty RAM in bank 0
FEB16 51365 offensive_Jerk 5150 RAM  Faulty RAM in bank 0
APR16 52129 gleegum 5160 Tantalum cap  C56 (sits on +12V line)
APR16 52130 offensive_Jerk 5170 IC  Type 1 motherboard.  Faulty MC146818
APR16 52214 prime 5150 IC  16KB-64KB board.  Faulty U15 and U17 and U23.
APR16 52214#17 prime 5150 Tantalum cap  C7 nearest U5 (sits on -12V line).  Repaired in March.
SEP16 53993 astamp 5160 Tantalum cap  C58 (sits on -12V line)
NOV16 55099 lutiana 5170 RAM  Type 1 motherboard.  One chip in bank 0.
DEC16 55460 Flamin Joe 5150 Tantalum cap  Quote: "shorted Tantalums on the 12V rail"
JAN17 55697 offensive_Jerk 5150 Tantalum cap  Linked video showed the one on the +12V line.
MAR17 53091 gigabajcior 5170 RAM delay line  DS1010-200
MAR17 56687#39 paperinik77pk 5160 Tantalum caps + RAM  Quote: "two 12v tantalum capacitors and some bad 4164 chips"
APR17 57300 Microfinne 5160 Tantalum caps  C56 (sits on +12V line) and C58 (sits on -12V line)
MAY17 57827 RadRacer203 5150 Tantalum caps  C6 (sits on +12V line) and C7 (sits on -12V line)
NOV17 60511 KLund1 5150 Tantalum cap  
MAR18 62567 jesolo 5150 RAM  RAM related problem
JUN18 64055 KLund1 5150 Tantalum cap  16KB-64KB board.  Quote: "C6 closest to the white power connector."  (This sits on -12V line.)
JUL18 64812 rvdbijl 5150 RAM  16KB-64KB board.  One chip in bank 0.
AUG18 65404#13 David_M 5170 Various  ROM + RAM
AUG18 65404#13 David_M 5170 Various  ROM + RAM + CPU
OCT18 66276 lutiana 5150 Various  16KB-64KB board.  ROM + RAM + [RAM refresh problem]
NOV18 66662 organizethis 5160 Tantalum cap  C58 (sits on -12V line)
DEC18   Flamin Joe 5170 IC  Type 1 motherboard.  Faulty MC146818
JAN19 68116 mykrowyre 5155 Tantalum caps  C56 (sits on +12V line) and C58 (sits on -12V line)         (plus tantalum cap on video card)
FEB19 68126 romanon 5150 IC  16KB-64KB board.  Faulty 8237 DMA chip.
FEB19 68301 Pekopome 5155 Tantalum cap  C56 (sits on +12V line)
JUN19 70470 mrmanse 5155 Tantalum caps  C56 (sits on +12V line) and C58 (sits on -12V line)
AUG19 71104 MikeTwain 5160 Tantalum caps  C56 (sits on +12V line) and C58 (sits on -12V line)
AUG19 70615 KLund1 5150 RAM  16KB-64KB board.  Multiple faulty RAM chips in bank 0
SEP19 71459 dabone 5150 Tantalum cap  Quote: "... and it ended up being a shorted 12v cap"
SEP19 71466 flyingji5 5170 IC  Faulty D82284-6
NOV19 48683#24 tonata 5160 Tantalum cap  C56 (sits on +12V line)
JAN20 73205 Smack2k 5160 RAM  No longer seeing RAM above 256 KB.  Cause: Bad RAM chip in 256-512KB bank
FEB20 73675 Old_hitech 5150 Various  16KB-64KB board. One cap on the +12V line, plus some yet-to-be-determined causes.
FEB20 73757 Dani G 5162 IC  Faulty MC146818
APR20 74333 NoSmoke 5150 Tantalum cap  16KB-64KB board. One cap on the +12V line.
APR20 74544 singlethread 5160 Tantalum cap  C58 (sits on -12V line)
JUL20 75923 Gary C 5160 Tantalum cap  C56 (sits on +12V line)
JUL20 40043 Alfred Werner 5160 BIOS ROM  Faulty BIOS ROM, U18



Some of my own motherboard repairs.
All motherboards had a 'dead / no display' symptom.

Date Motherboard Cause   Comment
NOV08 5150 Faulty RAM chip  16KB-64KB board.  One faulty 4116 RAM chip in bank 0
NOV08 5170 Faulty RAM chip  
AUG09 5150 Faulty 74LS138 chip  Thermal.  Chip worked when cold.
JAN10 5150 2 x tantalum caps plus 3 x RAM chips  
FEB10 5160 RAM delay line  
OCT19 5150 Various Prior to my acquisition of the motherboard, the motherboard had had a card fitted where, many years ago, the on-card battery had leaked.
1.   Discovered some faulty chips (right next to the slots).
2.   No damaged tracks, but there were what could be called damaged vias.   Those vias were some of the many where the solder in the component side of the via had become very dull and had become concrete like.   The photo at here shows my bypassing of the damaged vias, using wire-wrap wire.