9114B Charger PCB Repair


My 9114B just died after an hour of continuous use. I replaced the power supply with another and the drive came alive (sigh of relief). The battery is new (<24 hours old) and reads 6.5V. The drive worked for hours yesterday until the battery was drained. I left the battery charging over night and started testing again today for an hour at least.

I suspect the charger PCB is blown. I have no idea how to repair it. I am seeking advice.

  1. Is this a common issue, if so what components were the most problematic? I've repair/refurbished 5 other drives and have noticed that the PCB is not always the same. Interesting, but not useful today.
  2. Am I just better off hardwiring a 6V 2A PS?
  3. Anybody got a spare charger PCB for sale/trade?


Edited: 19 Sept 2008, 2:05 p.m.


Egan, have you opened the battery? I have one that actually had a fuse in it. I replaced the fuse and lead acid battery and voila!
Hope this helps.


The battery does not appear to open up. A volt meter reads just under 6.5V. I think the battery is OK and that the recharging circuitry may work, but the part of the circuit that delivers power to the drive is delivering nothing.



Egan, I should have stated that the white case enclosing the battery has several torx bolts holding it together. I removed the battery on mine and found that the fuse was there next to the PC board.


Ok, that's different. I thought you meant the battery inside the battery pack.

BRB, going to look for a fuse...

Nope, nothing that resembles a fuse to me.

Thanks again.


As far as I know all versions of the 9114 battery pack have a fuse on the charger PCB. On earlier models it's 2A, later ones are 5A. It's a little wire-ended 'Picofuse' and I think it's close to the 5 pin connector.

This is the only component between the battery and the 2 pin socket to the drive. If you're getting 6V at the battery and nothing at the drive then most likely that fuse has blown. Trace the connections to find it.

If the fuse has coloured bands rather than a printed value, read them like a resistor, but in _mA_. In other words green-black-red is 5000mA or 5A.

There are, indeed, 2 versions of the charger PCB. The one used in the -A battery (officially for the 9114A drive only) is a simple linear regulator. The one used in the -B battery (for all 9114s) is an SCR-based circuit IIRC. Schematics for both (and the rest of the 9114) are on the Australian site. That site has recently been modified and now has one of those infernal 'type in this munged word' anti-web-bot things :-(


take at look at this The MoHPC 9114 Repair manual it might have some more info with regards to what you are looking for. There are schematics of the charger unit, how to open and replace the battery pack, what the fuse looks like (like a diode) etc...




Jeff, Peter, Tony,

Thanks, I found the fuse. Now, where do I find a replacement? The link in Peter's guide (thanks, I completely forgot about it), is dead.

Will this work:



Edited: 20 Sept 2008, 1:03 p.m.


In a pinch you can use a piece of #34 awg wire to achieve a 5 amp fuse value. Just wrap it around a small resistor or the old fuse, solder and cover with tape or tubing.

You can find #34 wire in a piece of #26 stranded wire which usually has 7 strands of #34 inside...


That fuse looks perfect to me.

It appears, though, that you have to buy 10 of them (no big deal) and that it's coming from Farnell in the UK and you have to pay $20 handling (I, being in the UK, have the same problem when Farnell list something that really comes from Newark).

You may find a US supplier of them, I don't know.


Digikey is one of the better if not best US supplier for small quantities. They have 11K pieces in stock:


I would like to bypass the battery and associated circuit in the battery plastic case. What DC voltage and rating should I feed to the 9114B battery pack (with the innards bypassed)? A transformer that supplies 6V DC with 2A current?


Tony, Randy,

I ordered 3 for just a bit over $1 from Mouser. Shipping was about $6.


Jeff, Peter, Randy, Tony,

Thanks for your help. It was the fuse. I replaced it with Littelfuse PN: 0251005.MAT1L. Cost: $0.39 US.

Peter, for your guide:


great, very happy it is working again! Thanks for the pic, I'll add it to the guide this weekend.




For printing purposes you may prefer the original hi-res version posted here http://sense.net/~egan/IMG_6393.jpg.

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