Batboard

Hi all,
I am new to this board and excited to find one almost exclusive to Motorola products. The smoke was let out of the RT1 and RT2 on the A3 Power Supply board (they litterally exploded) of my R2008D SM. Does anyone have, or can tell me where I can obtain, a schematic and PC board trace lay-out?

I don't think RT1 & 2 are MOV's and are probably required for this PS board to operate properly. Some traces around the BR1 were burned away.
The number of the board itself is "94990ASSY01-P22031E001" No Revision, Ser. no D3377 I have a picture but have no autorization to attach any to the post.

Thanks in advance and if you wish, please contact me direct at "ve3dwi at xplornet.com"

Tony.

Hello Tony.

Welcome to the board. It sounds like the monitor was plugged into 220 VAC when it was set for 110 VAC operation. If that was the case, there is a protect circuit (DS1?) under the motherboard that will also be blown. Your email address indicates that you are not here in the U.S. so let me know where you are and I'll try to find someone from Motorola that can help you. I had 25+ years in Motorola's Test Equipment Service Depot and know quite a few of the international techs. The R2000D series still has support (at least here in the states), but it can be expensive. On Monday I'll call the depot and find out what I can about RT1 and RT2 for you. Unfortunately I wasn't allowed to bring my maintenance manual with me when I was "retired".

Hi Dave,

Thank you very much for you're reply. The monitor was not plugged into 240 V as it has been on my hobby bench for months and has been used fine all along. It just died with a bang one day when I turned it on. That's when I discovered the exploded RT part. That's not to say that there is not something else wrong.

RT1 is directly connected to the negative pin of the bridge rectifier. Then it goes on to a 3300uF 250V Capacitor and a high wattage resistor etc. RT2 is similar but goes to the positive pin of the bridge rectifier etc. I can't help but thinking that they may be part of an inrush current limiting system. It would be great if you could come up with the schematic of this P.S. It would be a big step in the right direction. If you want to, I can email a picture of the board to your private address. Many Tnx.

Tony, VE3DWI

Hi again Dave,

I forgot to tell you where I am located. I am in Northern Ontario Canada in a town by the name of Desbarats which is 25 mls East of the Sault Ste Marie Michigan border (all the way up in the Upper Peninsula) where Ontario and Michigan join at the South/Eastern tip of Lake Superior.

Regards,
Tony, VE3DWI

A3RT1 & RT2 are thermistors. Motorola p/n 0680342B85. Still available but (as usual) expensive.