Bonanza pilot reported a series of equipment malfunctions and returned to departure airport.

Narrative:

After [takeoff] ZZZ tower notified me on negative transponder signal. I acknowledged and attempted to reset. The tower then gave me a frequency change to [TRACON]. Right after contacting [TRACON] I noticed my back up radio went black. ATC cleared me to climb to 6500 feet and verified my location. Within 30 seconds of conversation with ATC my aspen primary flight instrument went black. I immediately requested to return back to ZZZ and checked and cycled fuses and avionics power after verifying proper volts on the jpi engine monitor. [TRACON] handed me off to ZZZ tower who asked if everything was ok and I responded with instrument failure. They immediately cleared me to enter left pattern for xxl cleared to land number 2. Within seconds of that call my garmin 650 primary radio went black and 30 seconds later I lost my jpi engine monitor. I landed safely on xxl at ZZZ but was unable to transmit 7600 or communicate with tower or ground.

Original NASA ASRS Text

Title: Bonanza pilot reported a series of equipment malfunctions and returned to departure airport.

Narrative: After [takeoff] ZZZ tower notified me on negative transponder signal. I acknowledged and attempted to reset. The tower then gave me a frequency change to [TRACON]. Right after contacting [TRACON] I noticed my back up radio went black. ATC cleared me to climb to 6500 feet and verified my location. Within 30 seconds of conversation with ATC my Aspen primary flight instrument went black. I immediately requested to return back to ZZZ and checked and cycled fuses and avionics power after verifying proper volts on the JPI engine monitor. [TRACON] handed me off to ZZZ tower who asked if everything was Ok and I responded with instrument failure. They immediately cleared me to enter left pattern for XXL cleared to land number 2. Within seconds of that call my Garmin 650 primary radio went black and 30 seconds later I lost my JPI engine monitor. I landed safely on XXL at ZZZ but was unable to transmit 7600 or communicate with tower or ground.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1602858
Time
Date	201812
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Bonanza 33
Operating Under FAR Part	Part 91
Flight Phase	Initial Climb
Route In Use	Direct Visual Approach
Flight Plan	VFR
Component
Aircraft Component	Electrical Power
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 20 Flight Crew Total 335 Flight Crew Type 250
Events
Anomaly	Aircraft Equipment Problem Less Severe