Cobra 142gtl dk no audio, has audio on ssb

[Wky Gatekeepr]

I’m very new to this works and trying to learn minor repairs to cb radios. We were trying to wire a workman dm502b to the 142 and somehow shorted pin 3&4 of the mic plug, we heard a sizzle sound and the radio quit modulating in AM ONLY. Looking for a little guidance in aiding the repair. Receive works great and Ssb works great, just lost audio on AM as mentioned.

And if someone has a wiring diagram for the Workman DM502b for the 142 that would be great as well..

TYI

 

[brandon7861]

Pin 4 is ground. Shorting pin 3 to ground shorts the output of the audio amplifier to ground. Check IC4 (TA7222P).

 

[brandon7861]

C118 may have taken a beating too.

Under $5 total if one or both of these are bad.

TA7222AP Toshiba PLL/audio IC (NOS) - TA - Integrated Circuits

<p><strong><span style="font-size: medium;">TA7222AP Toshiba PLL/audio IC (NOS)</span></strong></p> <p><span style="font-size: small;">New Old Stock * No longer available for export</span><br /><span style="font-size: small;">MFR: Toshiba</span></p>

www.rfparts.com

470-25R, Radial Lead, Capacitor, 25v, 470μf, Pack of 2

470-25R, Radial Lead, Capacitor, 25v, 470μf, Pack of 2

www.rfparts.com

Mislabeled in title but the picture says it.

 

[Wky Gatekeepr]

C118 may have taken a beating too.

Under $5 total if one or both of these are bad.

TA7222AP Toshiba PLL/audio IC (NOS) - TA - Integrated Circuits

<p><strong><span style="font-size: medium;">TA7222AP Toshiba PLL/audio IC (NOS)</span></strong></p> <p><span style="font-size: small;">New Old Stock * No longer available for export</span><br /><span style="font-size: small;">MFR: Toshiba</span></p>

www.rfparts.com

470-25R, Radial Lead, Capacitor, 25v, 470μf, Pack of 2

470-25R, Radial Lead, Capacitor, 25v, 470μf, Pack of 2

www.rfparts.com

Mislabeled in title but the picture says it.

Thank you! I actually replaced c118 and 119 last night and found the TA 7222p grounded.