# Kenwood TH-D72 Freeze on Splash Screen

Some friends and I recently placed a Kenwood TH-D72 on the summit of Saddle Mountain in Oregon, USA, and set it up as a temporary digipeater for use with APRS.

The TH-D72 successfully digipeated packets, but when our hiker summited the mountain again the next day, he found that TH-D72 was stuck on the startup splash screen and was unresponsive to any button presses (other than powering off).

I haven’t been able to find any reports of a TH-D72 freezing on the startup splash screen. Does anyone have experience with this? What is a likely cause of this behavior? We haven't seen the TH-D72 freeze on the splash screen before or since.

The sequence of events is roughly as follows:

2017-08-25 15:10:33   -   Hiker sets up TH-D72 and manually sends first APRS beacon.
2017-08-25 16:30:00   -   Hiker descends mountain and leaves TH-72 on summit.
2017-08-25 19:15:44   -   First vehicle comes in range and TH-D72 digipeats an APRS position packet.
2017-08-26 05:09:17   -   Final digipeated APRS packet (all vehicles may have gone out of range at this point).
2017-08-26 06:54:40   -   Final automatic APRS beacon sent from TH-D72 (it seems to have sent beacons up to 00:30:00 apart).
2017-08-26 07:45:40   -   Hiker summits mountain again and finds TH-D72 stuck on the startup splash screen.


The radio was powered by YUASA NP7-12 12V,7.0h battery and 12V to 7.5V switching regulator. The battery manufacturer recommends keeping the battery between –15°C and +50°C for charging and discharging. The temperature on the summit was likely between 4°C and 32°C. The enclosure was vented with a fan.

Two days after the hiker retrieved the enclosure with the radio and battery, we started up the TH-D72 and it successfully sent several APRS beacons. It did not freeze up. The voltage droop during packet transmission was minimal:

• Things can freeze for all kinds of reasons, but the standard solution to this sort of thing is a watchdog timer. – Phil Frost - W8II Aug 30 '17 at 20:00
• @Phil Frost - Any implementation ideas? I might be able to detect the lack of operation with a photo diode taped on the red transmit LED and turn off the radio. But how would I turn on the TH-D72? I believe you need to press a button the front. – watkipet Aug 31 '17 at 18:30
• Possibly unrelated, but have you checked/properly configured the automatic power-off setting? That wouldn't explain the freezing, but it could be causing the radio to shut off in the first place. – Rafael KR7MJ Sep 1 '17 at 15:18
• Battery: Automatic Power-off and Save were both turned off. – watkipet Sep 1 '17 at 17:08