Intel Pentium 66mhz Boot Issues

Discussion about old PC hardware.

Intel Pentium 66mhz Boot Issues

Postby fsmith2003 » 2017-11-25 @ 00:02

I took a chance on a untested as-is Intel socket 4 on ebay. The machine arrived today and there are in fact issues that I cannot decipher and was hoping to find some help here. The board part # is an Intel PBA 619773-008. I think this may be one of the "Batman Revenge" mb's? The issue I am having is that when the computer is turned on it will show the beginning of the bios screen and say press F1 to go to setup. Then at the bottom it will say Keyboard Detected. However at this point I am unable to progress any further.

I was able to press F1 if it was pressed instantly after boot up. It acted like it wanted to go to the setup screen but immediately froze again. Its as though after about 5 seconds it will freeze regardless of what buttons I press.

Another issue. After I have tried to turn it on a few times it will eventually stop turning on all together. It takes unplugging it for several minutes and then trying again just to get anything to come up on the screen but then I'm back to the first issue.

Would anyone have any ideas of what I should check to possibly get this going? Thanks!
User avatar
fsmith2003
Member
 
Posts: 279
Joined: 2016-11-01 @ 02:06
Location: Illinois (Not Chicago)

Re: Intel Pentium 66mhz Boot Issues

Postby Ampera » 2017-11-25 @ 01:38

Sounds like capacitors. I would replace them.

I would also check for generic shorts all around the board. Anything touching that shouldn't be. I had a 486 board that was shorting on a couple of standoffs and in my infinite wisdom it took me 2-3 days to figure that one out.

I would honestly start with those two and go from there. There's normally a reason people don't go for as-is boards as it's a cheeky way of saying not working without sounding as negative.
User avatar
Ampera
Oldbie
 
Posts: 901
Joined: 2016-11-16 @ 22:31

Re: Intel Pentium 66mhz Boot Issues

Postby luckybob » 2017-11-25 @ 03:13

I sell all my stuff as-is. even tested. just because I don't want to deal with returns.

Try slowing the FSB down to 60mhz instead of 66. Even though it was a defacto practice to run 60mhz chips and boards at 66mhz, some just couldn't handle it. Also check your ram. It needs to be rated for 66mhz, some old simms are not capable of it.
It is a mistake to think you can solve any major problems just with potatoes.
User avatar
luckybob
l33t
 
Posts: 3443
Joined: 2009-4-30 @ 04:43

Re: Intel Pentium 66mhz Boot Issues

Postby Koltoroc » 2017-11-25 @ 03:55

probably a dumb question, but does the CPU have a cooler? Those old Socket 4 pentiums NEED a cooler. they get way to hot. If it has a cooler that is not glued down reapply thermal compound.

Another thing to check is the cmos battery. Weird boot issues can be caused by a dead battery.
Koltoroc
Member
 
Posts: 260
Joined: 2016-10-07 @ 23:21

Re: Intel Pentium 66mhz Boot Issues

Postby fsmith2003 » 2017-11-25 @ 04:03

Koltoroc wrote:probably a dumb question, but does the CPU have a cooler? Those old Socket 4 pentiums NEED a cooler. they get way to hot. If it has a cooler that is not glued down reapply thermal compound.

Another thing to check is the cmos battery. Weird boot issues can be caused by a dead battery.


It has one of those Dallas RTC's Not sure if there is a way to check those? And yes there is a heat sink and fan on top of the CPU. It does get very hot I know. I am going to try using different RAM tomorrow and see if that changes anything as well.

I will also be looking over the capacitors to see if any look bulged or blown. Haven't really done a thorough inspection of it yet.

Keep the suggestions coming though i appreciate it!
User avatar
fsmith2003
Member
 
Posts: 279
Joined: 2016-11-01 @ 02:06
Location: Illinois (Not Chicago)

Re: Intel Pentium 66mhz Boot Issues

Postby amadeus777999 » 2017-11-25 @ 13:34

I too would opt for the caps but who knows. Be sure to put some thermal compound between the cpu and the heatsink... heat transfer needs to be optimal to have it running stable.
Could you post some pictures of said board and boot screen... maybe the bios too?
User avatar
amadeus777999
Member
 
Posts: 483
Joined: 2013-7-04 @ 17:04

Re: Intel Pentium 66mhz Boot Issues

Postby fsmith2003 » 2017-11-25 @ 16:35

Here are pics of the board and the screen I am stuck at. I’ve tried using a different psu, different ram, re-seated the cpu with new thermal paste, and triple checked the jumpers. Can not get it to post. Which capacitors should I be checking? Could it be possible that the cpu is bad or would it even get as far as it is if it were?

EC4D3C31-DE2F-45C5-BDAC-7B885F19B751.jpeg


2E4D5E2A-140D-4679-83AA-CE1C33DAEA38.jpeg
User avatar
fsmith2003
Member
 
Posts: 279
Joined: 2016-11-01 @ 02:06
Location: Illinois (Not Chicago)

Re: Intel Pentium 66mhz Boot Issues

Postby BastlerMike » 2017-11-25 @ 22:29

Had exactly the same problem with this board. You have to replace the RTC / do a battery mod on the RTC module.
User avatar
BastlerMike
Member
 
Posts: 191
Joined: 2010-10-11 @ 15:53

Re: Intel Pentium 66mhz Boot Issues

Postby fsmith2003 » 2017-11-25 @ 22:36

BastlerMike wrote:Had exactly the same problem with this board. You have to replace the RTC / do a battery mod on the RTC module.

Really!?? I hope that is all it is. I have seen several tutorials on modding the RTC. Which procedure did you do to take care of it?
User avatar
fsmith2003
Member
 
Posts: 279
Joined: 2016-11-01 @ 02:06
Location: Illinois (Not Chicago)

Re: Intel Pentium 66mhz Boot Issues

Postby fsmith2003 » 2017-11-26 @ 08:01

Well I replaced the two large capacitors. Still no luck. I wired up a cr2032 battery to the RTC. No luck. I have a couple more socket 4 CPU's coming in the mail. If a different CPU doesn't work then back to the drawing board i suppose.
User avatar
fsmith2003
Member
 
Posts: 279
Joined: 2016-11-01 @ 02:06
Location: Illinois (Not Chicago)

Re: Intel Pentium 66mhz Boot Issues

Postby amadeus777999 » 2017-11-26 @ 13:08

Thanks for the pictures.
Can't imagine the cpu being the culprit... only in a very rare case where an, especially frail, P60 may be running at 66 bus frq. and shortly thereafter just locks up due to excessive heat.
Unfortunately the cache is directly "pinned" onto the board, so if it has a faulty chip(unlikely) you're in for a ride. I do not see a socket'd bios chip - is it a more modern IC which also has been soldered onto the board?
User avatar
amadeus777999
Member
 
Posts: 483
Joined: 2013-7-04 @ 17:04

Re: Intel Pentium 66mhz Boot Issues

Postby fsmith2003 » 2017-11-26 @ 15:21

amadeus777999 wrote:Thanks for the pictures.
Can't imagine the cpu being the culprit... only in a very rare case where an, especially frail, P60 may be running at 66 bus frq. and shortly thereafter just locks up due to excessive heat.
Unfortunately the cache is directly "pinned" onto the board, so if it has a faulty chip(unlikely) you're in for a ride. I do not see a socket'd bios chip - is it a more modern IC which also has been soldered onto

I’ll be honest I’m not sure where the bios chip is either. It must be pinned somewhere because there is not a socketed one for sure.
User avatar
fsmith2003
Member
 
Posts: 279
Joined: 2016-11-01 @ 02:06
Location: Illinois (Not Chicago)

Re: Intel Pentium 66mhz Boot Issues

Postby amadeus777999 » 2017-11-26 @ 16:05

That sucks - unless it's a trivial problem causing the issue... you're on thin ice here.
The bios is only flashable via diskette not by "chip-switching" it seems. The bios chip itself seems to be the one left to the second ISA slot when starting from the top... the one with the sticker on top. No guarantee though.
User avatar
amadeus777999
Member
 
Posts: 483
Joined: 2013-7-04 @ 17:04

Re: Intel Pentium 66mhz Boot Issues

Postby TheMobRules » 2017-11-26 @ 16:20

amadeus777999 wrote:The bios chip itself seems to be the one left to the second ISA slot when starting from the top... the one with the sticker on top.

Yes, it's that one for sure.

Since you seem to be running out of options, here's another suggestion: maybe the voltage regulator next to the 2 big capacitors has gone bad? I don't know if it can be the cause of your problems, but they tend to run quite hot and this one isn't even heatsinked it seems.
TheMobRules
Member
 
Posts: 359
Joined: 2016-1-19 @ 23:29

Re: Intel Pentium 66mhz Boot Issues

Postby Ampera » 2017-11-26 @ 20:15

If you want to fix the RTC, just replace it. De-potting something like that is seriously not worth it.
User avatar
Ampera
Oldbie
 
Posts: 901
Joined: 2016-11-16 @ 22:31

Re: Intel Pentium 66mhz Boot Issues

Postby Mister Xiado » 2017-11-26 @ 20:54

From a chemistry standpoint, tearing the side of that damned Dallas chip open and attaching a CR2032 socket is the smartest way to permanently fix the problem (if that is indeed the source of the issue). I've got at least one board with similar problems (can boot fine, cannot install ANY expansion cards or access BIOS) myself, and it might possibly be the exact same board. If it wasn't currently buried under a pyramid of other boxes, I'd open it up to see.
The Homepage of the Oldternet - Where it's always 1992 (or so).
User avatar
Mister Xiado
Newbie
 
Posts: 78
Joined: 2017-9-12 @ 23:04


Return to General Old Hardware

Who is online

Users browsing this forum: appiah4, BLEXBot [Bot], Exabot [Bot], Neco, Rawrl, realoldguy23 and 9 guests