Dead BCD436HP

[chrgaughan]

I had my BCD436hp for 18 months or so, it just went dead and the batteries got very hot and I could smell an IC or so other component burning. It was in use for a few hours when this happened. Has this happened to anyone else ? I know there is an $80 charge to sent it in..

 

[ofd8001]

It's possible the original rechargeable batteries may have reached their end of life. Does it work with "regular" batteries (the non-rechargeable kind)? If so, replacement re-chargeables might be needed.

 

[chrgaughan]

Dead scanner

It has good batteries, it also does not power up using the USB cable, when it died it was plugged into the lighter plug in the car ( it blew the fuze on the adapter ) . Before it died it was working perfectly fine. I could smell smoke coming from the scanner, so something is shorted out

 

[ofd8001]

Sounds like a trip to Texas. $90 with shipping isn't all that bad when you figure parts are included and the scanner comes back just like new.


That said, I'd try to figure out what caused the problem so it doesn't get repeated after repair. Things usually don't go bad on their own. Typically an external influence is involved - just as an example connecting 12 volts to the input where it should be less, that kind of thing.

 

[chrgaughan]

dead

I have been using the same setup for 18 months and it was working fine.

 

[pro92b]

It has good batteries, it also does not power up using the USB cable, when it died it was plugged into the lighter plug in the car ( it blew the fuze on the adapter ) . Before it died it was working perfectly fine. I could smell smoke coming from the scanner, so something is shorted out

Check that car power cord and see if it is putting out 12 volts instead of 5 volts. The power cord may have killed the radio.

 

[pinballwiz86]

It has good batteries, it also does not power up using the USB cable, when it died it was plugged into the lighter plug in the car ( it blew the fuze on the adapter ) . Before it died it was working perfectly fine. I could smell smoke coming from the scanner, so something is shorted out

Cigarette lighter plug fried something in the scanner. Be sure to get a better quality cigarette lighter plug while you wait on the scanner to be repaired.

 

[ofd8001]

I have been using the same setup for 18 months and it was working fine.

Just because something worked fine 18 months doesn't mean anything. It's all about the very few moments just before you detected the unusual condition (smell smoke). Something went wrong in those few moments and the external power configuration is the primary, but not only, suspect.

It could have failed and sent an improper voltage to the scanner causing a component to react. I believe there may be a diode inside whose purpose is to regulate incoming voltage so the whole scanner isn't fried. The diode did what it was designed to - too much voltage and it gives out (like a fuse in an overcurrent situation). In other words the designed response to an improper condition.

 

[chrgaughan]

dead 436

I wonder if it's a 5 volt zenier or a general purpose type diode, does anyone know ?

 

[pro92b]

There isn't much information out there on the latest scanners that run on USB power. One schematic I have seen, not for the BC436HP, shows a 6.2 volt Zener connected across the 5 volt and ground pins of the USB jack. This is a tiny surface mount part, about 1/16" on a side, rated at 200 milliwatts. It wouldn't survive long if 12 volts at an amp or so were connected to the USB power pins.


The Zener would be near the USB jack if it is not blown clean off the board. Once the Zener is gone or open circuited, the 12 volts is free to destroy many of the components on the circuit boards which is what I believe happened. The Zener itself is too small to create any smoke upon failure. Other parts of the circuit did that. Replacing the Zener will not fix the radio. Replacement of one or more boards will be needed.


It would help to understand the failure better if you post the make and model number of the power cord along with the amp rating of its fuse.

 

[chrgaughan]

usb adapter

It was made by wireless gear and the model G0488,it has both the 1 and 2.1 amp jacks. I was plugged into the 2.1 amp side. I can smell smoke from it also...so that's probably what fried the scanner.

 

[Cepheid]

Does any repair dept troubleshoot and repair to component level anymore? My guess is they will replace the board. In my experience once you smell smoke it is toast. (pun intended)

 

[DJ11DLN]

Yes, once the magic smoke comes out it's almost always a bad thing.

If the adapter still functions at all it might be interesting to see what voltage it is passing. If something failed internally and somehow passed full automotive voltage to the scanner, I can't imagine that ending well. Powering these things via 5V USB may be convenient but if this is what happens when an adapter fails and isn't protected, a lot of our gear may be in danger.

 

[pro92b]

The RAVPower RP-VC006 car charger https://www.amazon.com/Charger-RAVP...1&ascsubtag=US-001-3239355-000-1439789-web-20 claims to have over voltage protection along with over current and over temperature. The allowable input voltage is 8 to 30 volts. If it meets its advertised claims, it should protect the device it powers. Most chargers of this type don't even mention protection features so this one is a bit unique (in a good way). Surprisingly I didn't see a device like this in Uniden's storefront.

 

[seth21w]

This is why i dont use car chargers for charging anything. My ex burned up her car from a cigarette charger being plugged in charging her phone. Whole dash melted!

 

[chrgaughan]

Dead 436

So I opened up the usb car charger, the 3 amp fuse did not blow BUT the positive lead of C1 burned in half to protect that fuse !! The voltage regulator has a big hole above pins 3 and 4 ( it's so burned I can't get a part number )

 

[chrgaughan]

fixed it

Well since the scanner was toast, and would cost $90 to fix, I opened it up and noticed that the voltage IC was burnt. I bought 3 of them from mouser for $7 and replaced it..It fixed it !! that IC is really small ( about 1 mm across)

 

[wbswetnam]

Congrats on the home repair, and saving yourself $90. Take a trip to a local steakhouse and have a big tasty ribeye. Take your repaired 436HP with you!

 

[safetyobc]

Well since the scanner was toast, and would cost $90 to fix, I opened it up and noticed that the voltage IC was burnt. I bought 3 of them from mouser for $7 and replaced it..It fixed it !! that IC is really small ( about 1 mm across)

Glad you were able to fix it yourself. Did this happen because you were charging the batteries in the radio or do you know what caused it?

 

[chrgaughan]

dead

No clue, I did have it on the charger while I was driving and I smelled something burning. There is a similar IC in other products that have the same problem. You can't remove the IC with a soldering iron. They are removed with very precise hot air soldering tips.