Rockbox mail archive
Subject: Re: Dead JBM 20
From: Markus Grebenstein (sassodimorte_at_gmx.de)
I'm not an electronic- expert two =-( You have to place one lead on the
case and one on 41 to check Logic- DC or 42 to check Motor- DC. To find
which is 41/42 two just check your HD. Normally pin 1 is marked
somewhere (on mine there's a sticker applied). The pins are numbered
with all even pins on top or on bottom (2,4,6,8..... next to each other).
> I'm not quite sure how I go about checking the voltage on the pins
> (i'm a relative electronics novice):
> Am I right to assume that I should take my multimeter, find the back
> of the PCB where the ATA connector resides (on my JBR v.1, it says
> MP3REAR-8.3), place one lead on pin 41 and other other on 42 and
> measure voltage - then repeat with HD removed?
> If so, could you help me locate which are the pins 41/42?
> Jim (8 days and counting since my JBR went R.I.P....)
> On Mon, 23 Aug 2004 15:52:21 +0200, you wrote:
>>Probably same problem as mine. Check voltage on pin 41 and 42 of ATA.
>>You have to measure with the HD disconnected and connected. On my unit
>>voltage goes down to 1.8V when the HD tries to spin up. Sadly I still
>>haven't found (what I'm looking for *g*) the bad guy on the pcb. Sadly
>>the schemes don't fit exactly to my JBS 20.
>>Linus Nielsen Feltzing schrieb:
>>>>Thank you for the suggestion - I had examined the battery connections
>>>>per that URL - they looked fine but I reinforced them anyway -
>>>>unfortunately, all to no avail. I also tried a different, fresh set
>>>>of batteries, but that too did not help.
>>>Hmmm. Can you measure the voltage on the HD? Check the ATA specification
>>>for the pinout.
>>>However, I suspect you will see 5V, but there isn't enough current to
>>>start the drive...
| Markus Grebenstein |
| Adalbertstrasse 88 80799 Muenchen |
| Tel.: 089/62509834 Fax.: 089/1488-269718 |
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