Thread
Notice to Powerbook Duo Users!
Well thats a good one actually.
It could be 33uf at 5.6v.
But it could also be 0.33uf at 57V. But i dont think so. I am betting on 33uf at 5.7V
Grab a meter and measure the DC at that cap during operation, thats how we will know for sure.
It could be 33uf at 5.6v.
But it could also be 0.33uf at 57V. But i dont think so. I am betting on 33uf at 5.7V
Grab a meter and measure the DC at that cap during operation, thats how we will know for sure.
Checked with a voltmeter with the power on. A steady 4.96 to 4.97 volts. Bam.
This means it's probably a 6v unit. I'll probably go with a 10v to be safe? I mean the thing was in pieces, the display was connected and on, trackball, a SCSI HDD, UltraDock, external FDD, no modem card, and a paltry 4MB RAM card.
From the very limited accurate information online, "5B7" refers to a case size. Which is about right since it's about 6mm x 7mm...ish. The actual voltage rating can be 4V to up to 63V. source
Since it says "33 EHA 5B7", 33 probably refers to ...I dunno, there's a possible match at 10v 33uF with a 5B7 case size. I don't care about the case size because of what I'm replacing all my caps with (electrolytic), I care about the capacity and voltage.
This means it's probably a 6v unit. I'll probably go with a 10v to be safe? I mean the thing was in pieces, the display was connected and on, trackball, a SCSI HDD, UltraDock, external FDD, no modem card, and a paltry 4MB RAM card.
From the very limited accurate information online, "5B7" refers to a case size. Which is about right since it's about 6mm x 7mm...ish. The actual voltage rating can be 4V to up to 63V. source
Since it says "33 EHA 5B7", 33 probably refers to ...I dunno, there's a possible match at 10v 33uF with a 5B7 case size. I don't care about the case size because of what I'm replacing all my caps with (electrolytic), I care about the capacity and voltage.
Well with the measurements you gave me, that cap is part of the 5V rail. So a 6.3v cap or a 10v cap would be fine.
But if it were me, i would get a 33uf at 16v.
But if it were me, i would get a 33uf at 16v.
Have you taken a look inside the PSU. It's recapping time there as well.
I replaced them with 33uf, 25v: given the power supply is at 24 volts, you're 100% sure it works.
I have recapped all my Duo's a while ago and use them regularly without problems. Always use a higher voltage when you're not sure.
Not exactly. Maybe in this case, but not all cases. power supply may be 24v, but there could be a 40v boost in there somewhere to feed passive panels. Now sometimes this voltage is built into a DC-DC circuit on the panel.
So dont take that for granted ;-) My previous point stands that it depends on the circuit.
So dont take that for granted ;-) My previous point stands that it depends on the circuit.
At what point would too much voltage rating effect the caps intended properties?
probably never. if your running a 50v cap in a 2v circuit, it isnt going to make a difference i dont think.
Now, running a 2v cap in a 50v circuit, well, you would have to try it.
Now, running a 2v cap in a 50v circuit, well, you would have to try it.
I've got both a Duo Dock and a mini Dock. Shame my Powerbook is stuck in the Duo Dock and I don't have the key.
I'll just have to find me a pick gun and have at it I guess.
I'll just have to find me a pick gun and have at it I guess.
The notice on leaking caps on the display PCB of PB Duos reminds me to the problem of moribund TFT panels in some PB 180 machines. Did someone investigate if the display malfunction might be caused just by a capacitor leakage and therefore could be fixed?
Use a Dremel and cut the Dock open?
Yes the Minidock also need recapping. So does the PSU of the large Duodock...
Well...
The recap job on both of the boards went smoothly. No hitches or hiccups on the way. I was pleased.
The End!
That...is what I was hoping for. Ughm...gonna need some tantalums. Not enough room on the display inverter board. PACKED in the display board, up the left side. Oops. We'll be okay. Definitely didn't see the 47uF 6v cap (I used 25v) near the top left corner of the keyboard coming. Can't put the keyboard down. Actually went not tooooo bad...bit of a problem removing the old tanks because of the tight proximity to each other. tsk tsk tsk
Pictures...maybe tomorrow. "How many pads did you lift?" Uhmm...ugh...a few
The recap job on both of the boards went smoothly. No hitches or hiccups on the way. I was pleased.
The End!
That...is what I was hoping for. Ughm...gonna need some tantalums. Not enough room on the display inverter board. PACKED in the display board, up the left side. Oops. We'll be okay. Definitely didn't see the 47uF 6v cap (I used 25v) near the top left corner of the keyboard coming. Can't put the keyboard down. Actually went not tooooo bad...bit of a problem removing the old tanks because of the tight proximity to each other. tsk tsk tsk
Pictures...maybe tomorrow. "How many pads did you lift?" Uhmm...ugh...a few
Thanks for the info about problematic caps. I've got a Duo 280c that needs inspection for this problem. The full Dock had the clicking problem a long time ago, but I never replaced the PSU caps. I did not think it was an operation I could handle myself. More recently, I recapped the PSU in my TiVo DVR, and that was rather easy. The Powerbook disassembly is a bit more intimidating, but I can handle it if I can find a clean surface to work on.
Can someone tell me if these issues are symptoms of the bad caps? The Duo runs fine when the battery is inserted and the power supply is connected, but the battery is not recognized. I used to be able to trick the Duo into seeing and charging the battery if I removed it for a few seconds and then reinserting it. That doesn't work anymore. If I remove the battery, the Duo will turn off after a few seconds. The Duo will not turn on unless both the PS and battery are connected. Resetting the Power Manager does not help.
Also on the capacitor agenda is a couple of my Quadra 840av motherboards. Hopefully they haven't damaged the MB yet.
Can someone tell me if these issues are symptoms of the bad caps? The Duo runs fine when the battery is inserted and the power supply is connected, but the battery is not recognized. I used to be able to trick the Duo into seeing and charging the battery if I removed it for a few seconds and then reinserting it. That doesn't work anymore. If I remove the battery, the Duo will turn off after a few seconds. The Duo will not turn on unless both the PS and battery are connected. Resetting the Power Manager does not help.
Also on the capacitor agenda is a couple of my Quadra 840av motherboards. Hopefully they haven't damaged the MB yet.
I feel like a complete dufus. It's been a while since I've posted anything on bulletin boards, and now I've managed to do it wrong. I messed up the italics BBCode in my previous post and now phpBB won't let me edit the post to make the correction. Very frustrating. I must be missing something obvious. Is it because the thread is a Sticky?