Jensen JHD910 Radio Repair

JHD910 picture

The Jensen JHD910 is a waterproof AM/FM and Weather radio designed for use in boats, golf carts, motorcycles, and other "outdoor" locations.

The JHD910 on my motorcycle died when the voltage regulator failed and the voltage shot up to 16 or more volts. The symptoms of the failure were that the unit would light up, display worked correctly, UI seemed responsive, but there was no audio out.

To debug the failure, I input audio to the "Aux In" jack on the front panel of the JHD910, and then looked at the pins on the audio amplifier chip. The audio was getting to the input pins, but nothing came out of the output pins. This suggested that the audio amplifier chip was dead.

The audio amp chip is a 15 pin SIP device, soldered to a daughter board with the necessary passive components, and then the daughter board is soldered at right angles to the main pcb. Fortunately the part number is visible on the chip; it's a Toshiba TA8238. These turn out to be available for under $10 each from various vendors on Ebay.com.

Disassembly of the JHD910 is straight forward; there are keyed plugs that allow the front and back halves to be separated. You'll need a #1 Philips for all of the screws (except maybe a #2 on the one that screws the audio amp to the heat sink).

Remove the daugher board from the main board by carefully using a solder sucker to remove the solder fillets that join the two boards. Be careful to not use too much heat and lift any of the pads off of either of the circuit boards.

I clipped the pins of the dead TA8238, unsoldered the 15 pins, cleared the holes in the daughter board, and soldered in the new part.

Re-solder the daugher board to the main board, make sure there's some heat sink paste between the amplifier and the heat sink, replace all the screws, and you're done. Careful to not torque the screws too much, they only thread into weak plastic bosses that crack quite easily.

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