68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.

PB3400 wont start

Posted by: MacUp72 on 2023-03-16 06:47:47 today I got a nice working Pismo 400 and a 3400, but this doesnt start at all. I already removed the PRAM battery, tried reseating everything, starting only with necessary hardware, but it doesnt even try to chime. I only can hear a tiny Pop from the speakers. Power adapter is working, the battery looks very good, no corrosion anywhere. Maybe the power connector on the board is cracked/bad, at the moment I try to remove the logic board to check for cracks or bad solder there. but I cant get it out of the chassis... the manual is a joke ( with modern powerbooks this is easier)

Posted by: 3lectr1cPPC on 2023-03-16 06:57:10 Getting a 3400 logic board removed is a real pain - I've done it and it involves a lot of finagling to get the darn thing out. I attack it near the area where the power board connects (bottom right, like the manual says, although I never even read it haha). First objective is to get the headphone jacks free from the case, then keep pressing right and forward towards you and eventually it will pop loose. Feels like you're going to break it and it bends slightly in the process, but there isn't a better way I know of. Neither of my boards suffered damage though. As for why your unit is dead, most likely suspect is the DC power board (board with the battery contacts on it). Start with replacing the two capacitors on it and hope to god it's that, but it often isn't from what I've heard. Something on them can just go bad. The other suspect would of course be the PRAM battery. You said the battery hasn't leaked, are you talking about the main or the PRAM? The main won't, it's lithium ion. double check the board under the PRAM battery, maybe you missed something, but if it isn't that, then I'm afraid you've likely fallen into one of the classic 3400 failure modes. You can try resoldering the DC jack but I honestly doubt it's that.

Posted by: MacUp72 on 2023-03-16 07:09:39 no PRAM didnt leak, the black cable did come off though..nothing on the board either. Battery looks ok, no corrosion. do these look bad? not too swollen..

Posted by: 3lectr1cPPC on 2023-03-16 07:12:06 they won't really "look" bad, these newer ones don't leak (yet). What they may be is out of spec, which can cause just as many problems. I have the values and reference images up on my website, though I do need to add some dimension measurements as multiple people have requested: https://macdat.net/cap_reference/apple/powerbook/3400c.html

Posted by: MacUp72 on 2023-03-16 08:27:24 ok, just found some corrosion under the PRAM battery, cleaned and scrubbed it with alcohol but no change.. strange, because the PRAM battery from the outside didnt leak ( I can see a corrosion inside the two PRAM cables though) bummer, because it has a CD drive..well better turn my attention to the Pismo now.. thanks PS, good site of yours

Posted by: 3lectr1cPPC on 2023-03-16 08:35:23 yep, that will do it. Doesn’t look too bad so you might be able to fix it, check for any bad vias and traces, resolder the affected components, etc. that stuff spreads easy! PS, good site of yours Thanks!

Posted by: MacUp72 on 2023-03-16 11:35:49 when I plug in my modded G4 power adapter a wiggle it a bit, the little led at the top of the monitor gets green.. at least😛

Posted by: 3lectr1cPPC on 2023-03-16 11:37:25 Funny thing is that it isn't actually supposed to do that - that light is just for blinking during sleep. If it's on solid, that's known as the Green Light of Death, which is almost always a power delivery failure of some kind, ie, the power board. Seeing as you have to wiggle it, give resoldering the DC jack a go. If you're lucky, that will be the only problem.

Posted by: MacUp72 on 2023-03-17 01:16:32 ok, I'll try a recap..on your reference site you already seem to have photographed some changed caps.. I'm not an cap expert, maybe you kindly could make an mouser ordering list with your correct cap models eg, the 100uF 35V seems to be this one, but your two 33uF 25V ? you have replaced both 33uF to Tantalum ones.. many thanks I also noticed theres a little bit of whitish covering on that coil on the left, this maybe normal, but I dont know.. ( have seen exploded cabs with the gut spilled over a board, but I cant see anything of this here basically) (

Posted by: 3lectr1cPPC on 2023-03-17 05:32:06 that doesn't look quite right to me based on the image I have of my power board, but it's hard to tell. I'll go through mouser and try to assemble a parts list, although I won't be able to validate 100% that everything will fit.

Posted by: 3lectr1cPPC on 2023-03-17 05:44:03 Pretty sure these are the 33uf caps I used (get two): https://www.mouser.com/ProductDetai...GAEpiMZZMsh%2B1woXyUXj9KDAa7IpJRW6/lC1SHudFk= pretty sure these are the 100uf 25v caps (get one): https://www.mouser.com/ProductDetai...EpiMZZMsh%2B1woXyUXj4jKQI6sNRw62TrqU%2BXpeYs= Display: Not sure which exact ones I ordered, just bought ceramic caps because they're small and there is extremely little space to solder on the LCD. You aren't really supposed to use ceramic caps on displays because it can cause problems on some panels, but they worked fine on mine. Here are ones with matching values, will probably fit because I just found two that matched the value and bought them when I ordered myself, but there's always the chance that they may not, hard to tell. 200uf 4v: https://www.mouser.com/ProductDetai...GAEpiMZZMsh%2B1woXyUXj1nTw/Km/cPwvOtv47gDNio= 22uf 16v: https://www.mouser.com/ProductDetail/KYOCERA-AVX/1206YD226MAT2A?qs=ICeuwU4uWg30c4w3mpe%2BkA== Inverter board: 10uf 50v, fairly sure these are what I bought: https://www.mouser.com/ProductDetail/Vishay-Sprague/293D106X9050E2TE3?qs=N31o%2Bt096gu9lsvzLRhHsg== 2.2uf 50v, ceramic cap because it needs to be small. Don't remember ordering a Samsung cap before but it should fit as these ceramic caps are teeny tiny: https://www.mouser.com/ProductDetai...EpiMZZMukHu%2BjC5l7YRMZipZFyP%2B4GmTuMs4UQeM= There you go, no guarantees but these should work.

Posted by: MacUp72 on 2023-03-17 06:31:29 very sorry, but your links dont work .. you coud just copy/paste the partnumbers.. thanks

Posted by: 3lectr1cPPC on 2023-03-17 06:38:45 That is very strange. I get an error as if the site is down from my phone, but the site and links work fine on my computer. Hmm.

Posted by: 3lectr1cPPC on 2023-03-17 06:42:59 Let's try this instead... 33uf 25v (2x): https://mou.sr/406sryO 100uf 25v (1x): https://mou.sr/3TkQnfH 220uf 4v (1x): https://mou.sr/3JqzX0x 22uf 16v (1x): https://mou.sr/3VxSUDU 10uf 50v (1x): https://mou.sr/3lklkUC 2.2uf 50v (1x): https://mou.sr/3Fvtssi Edit: Rats! Doesn’t work from my phone either! It says something’s up with the site in the error, just try waiting a bit and hopefully it will fix itself. Links are direct from their share function so they should work.

Posted by: 3lectr1cPPC on 2023-03-17 08:04:15 Seems to be working now!

Posted by: MacUp72 on 2023-03-17 08:08:54

Posted by: 3lectr1cPPC on 2023-03-17 08:22:05 Does that mean they still aren't for you?

Posted by: MacUp72 on 2023-03-17 08:33:22 maybe its a good idea, if you just paste the parts/article numbers..not links or your list. I look it up myself at mousers germany, also was loking at Conrad but these look very different and are not available..

Posted by: 3lectr1cPPC on 2023-03-17 08:36:38 Same error I was getting... Part numbers: 74-593D25V33D 710-865080545012 581-F950G227KAAAQ2 581-1206YD226MAT2A 74-293D106X9050E2TE3 187-CL21B225KBYNNWE

Posted by: MacUp72 on 2023-03-17 11:13:53 interesting, while researching for other sources for those caps I chatted with my cousin, an experienced electronic specialist/ serviceman ( he rapaired TVs, HiFi, Pc, amplifiers etc for 35 years). He said, he would NEVER replace those old SMD eletrolytic caps with tantals, tantals were thought to be something special a few decades ago, but they turned out as inferior. He NEVER replaced elkos with tantals in his shop for clients. The build quality of todays elkos is much higher than before, I now just replace it with 105 degree electrolytic ones, in particular the 100 uF 35V. he is 80% sure in the case of this power board it is these two old elkos..

1 >