BC100/BC200: BC200XLT opening case

[kg9qm]

I am trying to open the case on my old BC200XLT scanner, which has ceased to power up despite the battery being charged. It was working fine last time I used it (long time ago).

I hope I can resurrect it. As I recall, it was always rather finicky about battery voltage and would not wake up on low batt.

I put it on a 7.4v bench supply (direct to the bottom contacts and not through the battery) and still no wake up.

I have the two black screws on the back removed, as well as the 3 silvery screws on the bottom. Also the two knobs on the top.

Anyone know how to safely pry the case open, before I break it? No idea if I need to slide or pop it off. Removing the screws didn't seem to loosen anything.

 

[n1chu]

The obvious edit is to first change the title from SDS200 to SDS100.

As for the case removal I can only mention the radio is supposed to be water/moisture resistant to so many meters of water for a certain length of time. (I have not attempted to open mine up but have opened the BCD436HP which is an entirely different case.) That means there is a seal that must be considered if you want to take apart the radio and not do any damage to the seal, not that you really need it. I don’t go swimming, take long walks in the rain or shower with mine but when you do learn how to open it up, you should try to preserve any type of sealing system being used.

 

[doctordialtone]

The obvious edit is to first change the title from SDS200 to SDS100.

Nope
There's a service manual listed here:

BC200XLT - The RadioReference Wiki

wiki.radioreference.com

 

[n1chu]

Nope
There's a service manual listed here:

BC200XLT - The RadioReference Wiki

wiki.radioreference.com

I stand corrected. I saw “200” and thought it read SDS200. But all is not lost… the BC200 looks to share the same case as the 436 which I have opened. I experienced no issues with it and followed no written proceedure. I winged it. I went slowly and did not force anything. But I took my time. Look for additional screws inside the battery case too.

 

[pb_lonny]

the BC200 looks to share the same case as the 436 which I have opened.

Totally different radio from a different era...

 

[KevinC]

I stand corrected. I saw “200” and thought it read SDS200. But all is not lost… the BC200 looks to share the same case as the 436 which I have opened. I experienced no issues with it and followed no written proceedure. I winged it. I went slowly and did not force anything. But I took my time. Look for additional screws inside the battery case too.

Say what? Not even close.

 

[Ronaldski]

You mention 7.4 Volts, maybe not enough current?

The following is what I have seen and read several times elsewhere although its concerning the battery pack, may not pertain at all to your issue though, but just 'food for thought'.
Battery circuit board, I had a 200xlt do the same and Ive seen many others report the same issue.

Way I got mine to work on batteries was to use a cord for the plug of the cigarette lighter power in the car or use the ac adapter and plug into the radio battery pack and it will start. Removed the power, its fine on batteries, just dont turn it off when your away from either power sources and power cables.

Other thing to check, is use isopropyl alcohol and swab the connecters on the battery case and radio to remove any dirt so it will make good contact.

 

[kg9qm]

My bench supply has plenty of current capability. I already had the manual which makes no mention of how to get into the thing.

Guess I'll keep prying in hopes I don't break any internal clips, which I am very good at doing, unfortunately.

Edit: I kept at it and finally the back tilted out from the bottom edge. Seemed to be lightly glued probably from perspiration.

 

[kg9qm]

For what it's worth, here's a look inside at the 34 year old technology. Two boards stacked via an 18 pin DIP connector

 

[n1chu]

Totally different radio from a different era...

It looks like it uses the same case. Manufacturers commonly use the same housings for newer models. If you don’t have specific differences relating to the case alone, (not the era or guts of the radio), my post stands as is.

 

[gspivey]

I have a radio exactly like this with the same problem, so if you figure out the problem I’d be interested in knowing what it is!

 

[pb_lonny]

I am sorry, but these are totally different radios...

 

[KevinC]

It looks like it uses the same case. Manufacturers commonly use the same housings for newer models. If you don’t have specific differences relating to the case alone, (not the era or guts of the radio), my post stands as is.

Umm…no.

 

[kg9qm]

Very hard to probe much on the board so I've had to order some header connectors to make a cable that will let me separate the two halves.

I was able to confirm the b+ gets onto the boards but I can't trace the interior paths because they are facing together via a board/board 16 pin header.

IC207 puts out a signal for low battery protection and where it goes to I can't check but evidently is telling the rest of the system to turn off. via a reference voltage at D203/IC202 being below threshold. But I can't check if the b+ gets there or gets reduced to 5v.

I suspect 5v regulator IC202 is open.

 

[kg9qm]

After making a ribbon cable jumper to allow the PCB sandwich to be separated, I traced the pinouts (for some reason not labeled in the service manual).

I was able to determine the S+B was not coming up to 7.2V. So apparently the power switch wasn't closing contacts.

I located the S+B (switched B+) and UNS+B (unswitched B+) contacts. Shorting them made the radio turn on.

There was no way to access the on/off switch to test it (all pins are under a copper back shield) so I tried spraying the exterior of the control with contact cleaner and...

The radio powers up again.

[I also stuffed new NiCads in my battery packs. FYI, there are two black screws on the side and two tabs under the polarity label on the bottom that lock the halves together. The tabs are delicate - I broke one]

 

[rcool101]

I got 2 if somebody is interested. Hate to throw them in the garbage. They both power up. One is a Regency and the other Uniden. Uniden is in good shape. Batteries are shot. PM me if interested