Hi,
In the process of repairing a circuit board from a Roberts Dab radio. There is no signs of life and after removing the board I found a burnt ic. (pic attached). The trouble is I can't make out the chip type number due to the burning. It starts with PT 2*6* HT( I think). Iv'e looked everywhere for something like it but no luck. I have two questions: does anyone know what the number could be and does anyone have a circuit diagram for this board. ( Rambler BT-301-00). Any help would be greatly appreciated.

 

I can't make the numbers out, but it's an Audio amplifier chip by Princeton.tw

See if you can get the number by brushing it with cleaning fluid, and try and search for it here.. looks similar to the pt2831..

http://www.princeton.com.tw/en-us/products/multimediaaudioic/audiopoweramplifier.aspx

 

I can't make the numbers out, but it's an Audio amplifier chip by Princeton.tw

See if you can get the number by brushing it with cleaning fluid, and try and search for it here.. looks similar to the pt2831..

http://www.princeton.com.tw/en-us/products/multimediaaudioic/audiopoweramplifier.aspx

Thanks for that. Much appreciated.

 

Dodgydave, thanks to you I managed to find the correct ic from Princeton, it's a PT2369 HT 24 pin amp. Been trying to find this ic for ages! Cheers Dave.

 

Dodgydave, thanks to you I managed to find the correct ic from Princeton, it's a PT2369 HT 24 pin amp. Been trying to find this ic for ages! Cheers Dave.

Ha, I agree, I was just looking too and yes it has 24 pins and so does seem to be a PT2369, what's more the region of the chip's surface that looks burned seems to be right where the loudspeaker pins are situated, perhaps someone shorted the speaker?

But how exactly does one replace such a device? must be a bit of a struggle to desolder that old chip...

 

Dodgydave, thanks to you I managed to find the correct ic from Princeton, it's a PT2369 HT 24 pin amp. Been trying to find this ic for ages! Cheers Dave.

Here is the datasheet...

http://www.princeton.com.tw/en-us/products/multimediaaudioic/multiplefunctionaudioamplifier.aspx

 

Ha, I agree, I was just looking too and yes it has 24 pins and so does seem to be a PT2369, what's more the region of the chip's surface that looks burned seems to be right where the loudspeaker pins are situated, perhaps someone shorted the speaker?

But how exactly does one replace such a device? must be a bit of a struggle to desolder that old chip...

Hi, I cover the surrounding capacitors/connectors with aluminium tape, then presolder with low melt solder, then use the hot air gun to gently ease it off.

 

Hi,
I'm new here but I've replaced plenty of these audio chips in all the latest Roberts radios, ortus 2 & 3 and the play 10 & 20 model, and they use all the same audio chip but not all the pins are connected on the latter. To remove them I use my hot air station set at 420 deg c with plenty of flux on the pins, the chip does have a solder pad underneath it too so not just the pins. Another chip I've found blows 90% of the time is on the power board near the power in jack is the voltage regulator, its a 5 pin 5v in (pin 1) and 3.3vout (pin 5). Just make sure you have the mentioned volts at the corresponding pins if so then all good.

 

Hi,
I'm new here but I've replaced plenty of these audio chips in all the latest Roberts radios, ortus 2 & 3 and the play 10 & 20 model, and they use all the same audio chip but not all the pins are connected on the latter. To remove them I use my hot air station set at 420 deg c with plenty of flux on the pins, the chip does have a solder pad underneath it too so not just the pins. Another chip I've found blows 90% of the time is on the power board near the power in jack is the voltage regulator, its a 5 pin 5v in (pin 1) and 3.3vout (pin 5). Just make sure you have the mentioned volts at the corresponding pins if so then all good.

H Mick, have a found the 5 pin regulator (burn mark on pin 1)and the ic number is 333, don't suppose you have the usable part no for this? Appreciate your help.

 

H Mick, have a found the 5 pin regulator (burn mark on pin 1)and the ic number is 333, don't suppose you have the usable part no for this? Appreciate your help.

Hi,
Not sure if your in the UK but I got some from a company called Farnell, they were the quickest delivery for me but nowhere near the cheapest. I've since ordered some from China (AliExpress) which work out around 2p each, but take around 4-5 weeks to arrive. I could send you one or maybe 2 actually because they are tiny, if that helps but not sure how that would work on here though.
So pin 1 you should be getting 5v, pin 5 should be getting 3.3v. Off the top of my head I'm not sure about the other pins but I know that pin 4 isn't connected. Just lookup the pinout on that part number and it will give you all the info required. Hope that helps you.

 

Hi,
Not sure if your in the UK but I got some from a company called Farnell, they were the quickest delivery for me but nowhere near the cheapest. I've since ordered some from China (AliExpress) which work out around 2p each, but take around 4-5 weeks to arrive. I could send you one or maybe 2 actually because they are tiny, if that helps but not sure how that would work on here though.
So pin 1 you should be getting 5v, pin 5 should be getting 3.3v. Off the top of my head I'm not sure about the other pins but I know that pin 4 isn't connected. Just lookup the pinout on that part number and it will give you all the info required. Hope that helps you.

Thanks for your help(again)! Really appreciate it.

 

I would try to cut the pins off the chip, and then remove the pins one at a time.

 

I would try to cut the pins off the chip, and then remove the pins one at a time.

Thanks, I'll give it a go.

 

To remove them I use my hot air station set at 420 deg c with plenty of flux on the pins, the chip does have a solder pad underneath it too so not just the pins.

The above note from Mick says there is a thermal pad under the chip. If you havent got hot air then cutting the pins may just make it more difficult in terms of getting the pad underneath released. Maybe you can just set your iron to higher temperature and place it on the IC body... not sure if that would work.

 

Hi everyone,
I'm new here so please let me know if this question has been addressed before.
I am trying to find information/replacement on a 8 pin ic from a Roberts ortus 3 radio. It's on the power board and gets so hot that when put IPA on, it just evaporates immediately. The radio does actually work BUT the display is flickering hence the reason for me stripping it down.
I have googled the numbers on the chip but get nothing that looks similar,
I'm pretty sure the chip is some sort of voltage regulator but not sure as the stripe on the chip, is it something else completely different, because I'm new to repairing circuit I'm not 100%. I just need a little help in trying to find a replacement chip, I can buy the full power board from Roberts for around £14 but for the sake of a 5p ic then it's pointless buying the full board.
Any help would be appreciated.

 

Hi everyone,
I'm new here so please let me know if this question has been addressed before.
I am trying to find information/replacement on a 8 pin ic from a Roberts ortus 3 radio. It's on the power board and gets so hot that when put IPA on, it just evaporates immediately. The radio does actually work BUT the display is flickering hence the reason for me stripping it down.
I have googled the numbers on the chip but get nothing that looks similar,
I'm pretty sure the chip is some sort of voltage regulator but not sure as the stripe on the chip, is it something else completely different, because I'm new to repairing circuit I'm not 100%. I just need a little help in trying to find a replacement chip, I can buy the full power board from Roberts for around £14 but for the sake of a 5p ic then it's pointless buying the full board.
Any help would be appreciated.

That chip is an 8 pin buck regulator but it goes under a different number by Texas Instruments, the only number that brings back anything is Ti 6ba..

https://www.ti.com/product/TPS54428...VCJntCh3aiAhTEAAYASAAEgJXv_D_BwE&gclsrc=aw.ds

 

That chip is an 8 pin buck regulator but it goes under a different number by Texas Instruments, the only number that brings back anything is Ti 6ba..

https://www.ti.com/product/TPS54428...VCJntCh3aiAhTEAAYASAAEgJXv_D_BwE&gclsrc=aw.ds

Thanks for your quick response, I've just acquired another model from ebay, im going picking it up later today so I I'll measure the voltages on that one and try to find a similar one. I've never dealt with a buck converter before so its good to know.
I wish I could buy you a virtual pint. Thanks

 

I've done some voltage checks on my working Roberts ortus 3, and noted down the voltages I'm getting when switched on.

Will that buck regulator which you provided a link for be OK for my Radio?

https://www.ti.com/product/TPS54428...VCJntCh3aiAhTEAAYASAAEgJXv_D_BwE&gclsrc=aw.ds
https://www.ti.com/product/TPS54428...VCJntCh3aiAhTEAAYASAAEgJXv_D_BwE&gclsrc=aw.ds

Thanks

Thanks for your quick response, I've just acquired another model from ebay, im going picking it up later today so I I'll measure the voltages on that one and try to find a similar one. I've never dealt with a buck converter before so its good to know.
I wish I could buy you a virtual pint. Thanks

 

Hi,
In the process of repairing a circuit board from a Roberts Dab radio. There is no signs of life and after removing the board I found a burnt ic. (pic attached). The trouble is I can't make out the chip type number due to the burning. It starts with PT 2*6* HT( I think). Iv'e looked everywhere for something like it but no luck. I have two questions: does anyone know what the number could be and does anyone have a circuit diagram for this board. ( Rambler BT-301-00). Any help would be greatly appreciated.

Hi shooter,
Did you manage to sort your Roberts radio out?, I've just acquired one of these and as yours it's not powering up, I've changed the voltage regulator and still dead. I've ran out of time today but will have another look tomorrow. Just wondering if you found anything else wrong on the pcb.

 

I've done some voltage checks on my working Roberts ortus 3, and noted down the voltages I'm getting when switched on.
View attachment 293157
Will that buck regulator which you provided a link for be OK for my Radio?

https://www.ti.com/product/TPS54428...VCJntCh3aiAhTEAAYASAAEgJXv_D_BwE&gclsrc=aw.ds
https://www.ti.com/product/TPS54428...VCJntCh3aiAhTEAAYASAAEgJXv_D_BwE&gclsrc=aw.ds

Thanks

I don't know if it's the same pinout as the radio chip, you need to reverse engineer the pins around it to see if it compares to the new one.